Many say that kitniyot derivatives are good for Ashkenazim to use (see Be’er Yyitzchak #26). R’ Yitzhak Elchanan Spektor, who was the posek hador in Vilna, was matir kitniyot derivatives for Ashkenazim.

But, you can probably substitute any Pesachdika oil, like Nutola Walnut Oil or any other kind.